Oilfield operations, such as surveying, drilling, wireline testing, completions and production, are typically performed to locate and gather valuable downhole fluids. As shown in FIG. 1A, surveys are often performed using acquisition methodologies, such as seismic scanners to generate maps of underground structures. These structures are often analyzed to determine the presence of subterranean assets, such as valuable fluids or minerals. This information is used to assess the underground structures and locate the formations containing the desired subterranean assets. Data collected from the acquisition methodologies may be evaluated and analyzed to determine whether such valuable items are present, and if they are reasonably accessible.
As shown in FIG. 1B-1D, one or more wellsites may be positioned along the underground structures to gather valuable fluids from the subterranean reservoirs. The wellsites are provided with tools capable of locating and removing hydrocarbons from the subterranean reservoirs. As shown in FIG. 1B, drilling tools are typically advanced from the oil rigs and into the earth along a given path to locate the valuable downhole fluids. During the drilling operation, the drilling tool may perform downhole measurements to investigate downhole conditions. In some cases, as shown in FIG. 1C, the drilling tool is removed and a wireline tool is deployed into the wellbore to perform additional downhole testing.
After the drilling operation is complete, the well may then be prepared for production. As shown in FIG. 1D, wellbore completions equipment is deployed into the wellbore to complete the well in preparation for the production of fluid therethrough. Fluid is then drawn from downhole reservoirs, into the wellbore and flows to the surface. Production facilities are positioned at surface locations to collect the hydrocarbons from the wellsite(s). Fluid drawn from the subterranean reservoir(s) passes to the production facilities via transport mechanisms, such as tubing. Various equipment may be positioned about the oilfield to monitor oilfield parameters and/or to manipulate the oilfield operations.
During the oilfield operations, data is typically collected for analysis and/or monitoring of the oilfield operations. Such data may include, for example, subterranean formation, equipment, historical and/or other data. Data concerning the subterranean formation is collected using a variety of sources. Such formation data may be static or dynamic. Static data relates to formation structure and geological stratigraphy that defines the geological structure of the subterranean formation. Dynamic data relates to fluids flowing through the geologic structures of the subterranean formation, as well as pressure and temperature conditions. Such static and/or dynamic data may be collected to learn more about the formations and the valuable assets contained therein.
Sources used to collect static data may be seismic tools, such as a seismic truck that sends compression waves into the earth as shown in FIG. 1A. These waves are measured to characterize changes in the density of the geological structure at different depths. This information may be used to generate basic structural maps of the subterranean formation. Other static measurements may be gathered using core sampling and well logging techniques. Core samples are used to take physical specimens of the formation at various depths as shown in FIG. 1B. Well logging involves deployment of a downhole tool into the wellbore to collect various downhole measurements, such as density, resistivity, etc., at various depths. Such well logging may be performed using, for example, the drilling tool of FIG. 1B and/or the wireline tool of FIG. 1C. Once the well is formed and completed, fluid flows to the surface using production tubing as shown in FIG. 1D. As fluid passes to the surface, various dynamic measurements, such as fluid flow rates, pressure, and composition may be monitored. These parameters may be used to determine various characteristics of the subterranean formation.
Sensors may be positioned throughout the oilfield to collect data relating to various oilfield operations. For example, sensors in the wellbore may monitor fluid composition, sensors located along the flow path may monitor flow rates, and sensors at the processing facility may monitor fluids collected. Other sensors may be provided to monitor downhole, surface, equipment or other conditions. The monitored data is often used to make decisions at various locations of the oilfield at various times. Data collected by these sensors may be further analyzed and processed. Data may be collected and used for current or future operations. When used for future operations at the same or other locations, such data may sometimes be referred to as historical data.
The processed data may be used to predict downhole conditions, and make decisions concerning oilfield operations. Such decisions may involve well planning, well targeting, well completions, operating levels, production rates and other configurations. Often this information is used to determine when to drill new wells, re-complete existing wells, or alter wellbore production.
Data from one or more wellbores may be analyzed to plan or predict various outcomes at a given wellbore. In some cases, the data from neighboring wellbores, or wellbores with similar conditions or equipment is used to predict how a well will perform. There are usually a large number of variables and large quantities of data to consider in analyzing wellbore operations. It is, therefore, often useful to model the behavior of the oilfield operation to determine the desired course of action. During the ongoing operations, the operating conditions may need adjustment as conditions change and new information is received.
Techniques have been developed to model the behavior of geological structures, downhole reservoirs, wellbores, surface facilities, as well as other portions of the oilfield operation. Examples of modeling techniques are shown in Patent/Application/Publication Nos. U.S. Pat. No. 5,992,519, WO2004049216, WO1999/064896, U.S. Pat. No. 6,313,837, US2003/0216897, US2003/0132934, US2005/0149307, and US2006/0197759. Typically, existing modeling techniques have been used to analyze only specific portions of the oilfield operation. More recently, attempts have been made to use more than one model in analyzing certain oilfield operations. See, for example, Patent/Application/Publication Nos. U.S. Pat. No. 6,980,940, WO04049216, US2004/0220846, and U.S. Ser. No. 10/586,283.
Techniques have also been developed to predict and/or plan certain oilfield operations, such as drilling operations. Examples of techniques for generating drilling plans are provided in Patent/Application/Publication Nos. US/2005/0236184, US/2005/0211468, US/2005/0228905, US/2005/0209886, and US/2005/0209836. Some drilling techniques involve controlling the drilling operation. Examples of such drilling techniques are shown in Patent/Application Nos. GB2392931 and GB2411669. Other drilling techniques seek to provide real-time drilling operations. Examples of techniques purporting to provide real-time drilling are described in Patent/Application Nos. U.S. Pat. Nos. 7,079,952, 6,266,619, 5,899,958, 5,139,094, 7,003,439, and 5,680,906.
FIG. 2A shows a schematic view of a portion of the oilfield (100) of FIGS. 1A-1D, depicting the wellsite and gathering network (146) in detail. The wellsite of FIG. 2A has a wellbore (136) extending into the earth therebelow. As shown, the wellbore (136) has already been drilled, completed, and prepared for production from reservoir (104). Wellbore production equipment (164) extends from a wellhead (166) of wellsite and to the reservoir (104) to draw fluid to the surface. The wellsite is operatively connected to the gathering network (146) via a transport line (161). Fluid flows from the reservoir (104), through the wellbore (136), and onto the gathering network (146). The fluid then flows from the gathering network (146) to the process facilities (154).
As further shown in FIG. 2A, sensors (S) are located about the oilfield to monitor various parameters during oilfield operations. The sensors (S) may measure, for example, pressure, temperature, flow rate, composition, and other parameters of the reservoir, wellbore, gathering network, process facilities and other portions of the oilfield operation. These sensors (S) are operatively connected to a surface unit (134) for collecting data therefrom.
One or more surface units (e.g., surface unit (134)) may be located at the oilfield, or linked remotely thereto. The surface unit (134) may be a single unit, or a complex network of units used to perform the necessary data management functions throughout the oilfield. The surface unit (134) may be a manual or automatic system. The surface unit (134) may be operated and/or adjusted by a user. The surface unit (134) is adapted to receive and store data. The surface unit (134) may also be equipped to communicate with various oilfield equipment. The surface unit (134) may then send command signals to the oilfield in response to data received.
The surface unit (134) has computer facilities, such as memory (220), controller (222), processor (224), and display unit (226), for managing the data. The data is collected in memory (220), and processed by the processor (224) for analysis. Data may be collected from the oilfield sensors (S) and/or by other sources. For example, oilfield data may be supplemented by historical data collected from other operations, or user inputs.
The analyzed data may then be used to make decisions. A transceiver (not shown) may be provided to allow communications between the surface unit (134) and the oilfield. The controller (222) may be used to actuate mechanisms at the oilfield via the transceiver and based on these decisions. In this manner, the oilfield may be selectively adjusted based on the data collected. These adjustments may be made automatically based on computer protocol and/or manually by an operator. In some cases, well plans are adjusted to select optimum operating conditions, or to avoid problems.
To facilitate the processing and analysis of data, simulators are typically used by the processor to process the data. Specific simulators are often used in connection with specific oilfield operations, such as reservoir or wellbore production. Data fed into the simulator(s) may be historical data, real time data, or combinations thereof. Simulation through one or more of the simulators may be repeated, or adjusted based on the data received.
As shown, the oilfield operation is provided with wellsite and non-wellsite simulators. The wellsite simulators may include a reservoir simulator (149), a wellbore simulator (192), and a surface network simulator (194). The reservoir simulator (149) solves for petroleum flow through the reservoir rock and into the wellbores. The wellbore simulator (192) and surface network simulator (194) solves for petroleum flow through the wellbore and the surface gathering network (146) of pipelines. As shown, some of the simulators may be separate or combined, depending on the available systems.
The non-wellsite simulators may include process and economics simulators. The processing unit has a process simulator (148). The process simulator (148) models the processing plant (e.g., the process facility (154)) where the petroleum is separated into its constituent components (e.g., methane, ethane, propane, etc.) and prepared for sales. The oilfield is provided with an economics simulator (147). The economics simulator (147) models the costs of part or all of the oilfield. Various combinations of these and other oilfield simulators may be provided.